Why was Randi Rhodes important to progressive talk radio?

You nailed it - Randi Rhodes was absolutely crucial to progressive talk radio because she proved that a fiery, unapologetically liberal voice could dominate the airwaves and draw huge ratings. She brought a sharp, combative style that wasn't afraid to take on conservatives head-on, and that helped solidify Air America as a real player in the early 2000s, paving the way for other progressive hosts to follow.